I have a feeling at least one of my brake rotors is warped due to the fact that the car shudders under braking and this increases when the brake temperature increases. So how I tell if a rotor is warped or not? Thanks.

 

That is a good indication.

 

..................but how do I know which one(s) it is by looking at it or by doing some sort of test? I'd rather not just replace all of them.

 

you generally just have to worry about the front two... they don't need to be replaced, just resurfaced... a shop can do it relativly cheap...

 

Normally it is the front ones. You would always want to have them machined in pairs, so the chance that you will fix it by machining/replacing the fronts is very high. Probably the only way you can detect it, is to check the runout with a dial indicator.

 

That'd be the way to check.

A friend of mine was having the same problem. Checked it with a dial indicator and nothing out of the ordinary... a few thou runout. Yet the car had a real problem. Cleaned the rotors with an abrasive Hawk Blue pad and no more problems.
Not saying that your problem is not in fact a "warped" rotor, but it may be the same as we experienced.

Here's a link to the thread where more of this is discussed.
http://web.camaross.com/forums/showt...5&pagenumber=2

Good luck.

-Mindgame

 

I think I will try that cleaning pad. Now that I think about it, what was said makes sense. The rotors look like they have some buildup on them.